The pilots “admitted to being very tired,” mission-control officials said.

Flight director Alan Noble said the propane fuel loss may have been temporary – caused by passing through clouds Monday night and Tuesday.

“If this is the case, then we will still have enough fuel to get to North Africa,” he said.

But the chances of reaching Egypt’s pyramids as Jones hoped are now “quite improbable,” the Geneva officials said in a statement.

Also, the temperature inside the capsule dropped from 59 to 46 degrees, possibly because a heater failed, they said.

Piccard and Jones, a 51-year-old former British air force pilot, lifted off from the Swiss Alps on March 1.

They took six days to cross the Pacific Ocean, perhaps the most difficult leg of the trip.

“So, that little puddle is what they call the Pacific?” Jones said as they left the ocean behind.

Pacific storms have forced other balloonists to curtail their bid to circumnavigate the globe.

Yesterday their Breitling Orbiter 3 craft left Belize for the Gulf of Mexico, after crossing Mexico at speeds of up to 115 mph.

They planned to pass between Jamaica and Cuba before heading out over the Atlantic.

One potential problem was erased yesterday when the Cuban government issued clearance for an overflight if winds force the balloon into their airspace.

The Anheuser-Busch company is offering a prize of $500,000 to the first person or team to complete the trip, and an equal amount to the charity of the winner’s choice.

American millionaire Steve Fossett, British tycoon Richard Branson and Per Lindstrand of Sweden were forced to ditch their balloon off Hawaii last December after flying around more than half the globe.